薄层稠油油藏蒸汽吞吐转热水驱的选区新方法

胜利油田郑364块稠油油藏由于层薄、油稠的特点,部分油藏进行蒸汽驱具有较大风险性。随着蒸汽吞吐轮次的增加,近井地带含油饱和度不断降低,开发效果变差。研究在稠油油藏注蒸汽开发以及转热水驱开发机理分析基础上,利用物理模拟研究了稠油油藏注蒸汽开发后转不同温度热水驱的驱油效率。通过对郑364块稠油油藏储层物性的分析,建立反映该稠油油藏特征的数值模拟模型。对其注蒸汽转热水驱的可行性进行了筛选研究。建立了考虑油藏渗透率、有效厚度和剩余油可动储量丰度的蒸汽吞吐后转热水驱筛选区块的新方法。该方法可针对薄层稠油油藏注蒸汽开发后是否能够转热水驱进行筛选分析。

A New Method of Selecting Zone for Thermal Water Flooding after Steam Stimulation in Thin Heavy Oil Reservoir

Most of heavy oil reservoirs for steam flooding have great risks due to thin thickness of resiervoir and high viscosity of crude oil in Zheng 364 block, Shengli oil field. Recovery efficiency gradually reduces as the cycles of steam stimulation increase resulting from remaining oil saturation decreasing near wellbore area in heavy oil reservoir. Experiments are employed to research the influence of injection temperature of thermal water flooding on flooding efficiency. Numerical simulation model is established to study the feasibility of thermal water flooding after steam stimulation in thin heavy oil reservoir. At last, a new method of selecting zone for thermal water flooding after steam stimulation are accomplished, which considers the relationships between the recoverable reserves abundance of remaining oil and reservoir geologic parameter, such as permeability and porosity in heavy oil reservoir. The method can be utilized to effectively analyze the feasibility of thermal water flooding after injection steam in thin heavy oil reservoir.